Components

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Components

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The project sidebar for this example is shown in the figure below. The project sidebar shows all of the components that are used in the example. Each of these components is described in detail in the following sections.

Project Sidebar for Example 5

Project Sidebar for Example 5

 

 

Project Component

When a new PipeLay project is created it contains just a Project component. This component is used to store general project information such as the project title, location, and so on. The Project component is also used to specify certain project-specific settings such as the system of units to be used, global constants, finite element mesh settings and quality control procedures. For this example, the following information is stored in the general Project Settings dialog.

Table: General Project Settings

Property

Value

Project Title

Example 5 - Structure Installation

Job Number

1-2-3-342

Engineer(s)

Wood Group

Location

Galway

For this example, the default Metric unit system and the default Constants dialog values are used. Also, the ‘Quality Control’ section is left as per default.

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Material Component

The Material component is used to define the physical properties associated with a particular material. This example contains two Material components, which define the material properties for both nonlinear X65 steel for the pipe section, as listed in the first table below, and linear steel for the cable, as listed in the second table below. The Material components are located in the Material folder and are named ‘X65 Steel’ and ‘Cable Steel’ respectively in this example.

 

Table: Material Properties for ‘X65 Steel’

Property

Value

Young's Modulus

207 GPa

Shear Modulus

80 GPa

Poisson’s Ratio

0.3

Mass Density

7850.0 kg/m3

Yield Strength

450 MPa

Allowable Stress

100 %

Allowable Strain

0.25 %

Expected Tension

1230 kN

Nonlinear Axial Stiffness

Yes

Use Criteria Tension

No

 

 

Stress-Strain Curve for ‘X65 Steel’

Stress-Strain Curve for ‘X65 Steel’

 

 

Table: Material Properties for ‘Cable Steel’

Property

Value

Young's Modulus

207 GPa

Shear Modulus

79.9 GPa

Poisson’s Ratio

0.33

Mass Density

7798.3 kg/m3

Coefficient of Expansion

0 1/c

Yield Strength

448 MPa

Allowable Stress

100 %

Allowable Strain

0.25 %

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Pipe Section Component

The Pipe Section component is used to specify the properties of an individual section of pipeline that has uniform properties. This example contains one Pipe Section component as follows:

The Pipe Section component is created in the Line folder and is named ‘24" Pipe’.

The specification is Standard.

The material used is ‘X65 Steel’, as defined previously.

The geometrical and hydrodynamic properties are listed in the table below.

Table: Properties for ‘24’’ Pipe’

Property

Value

Outer Diameter

609.6 mm

Thickness

27 mm

Normal Drag

1

Normal Inertia

2

 

Cable Component

The Cable component is used to specify the properties of an individual section of cable that has uniform properties. It is similar to the Pipe Section component in many respects, though less complex, as no additional coatings or attachments may be specified. This example contains one Cable component as follows:

The Cable component is created in the Line folder and is named ‘Yoke Cable’.

The Standard specification is selected and the material used is ‘Cable Steel’, as defined previously.

A relatively low bending stiffness of 0.01 kNm² is explicitly defined.

The geometrical and hydrodynamic properties are listed in the table below.

Table: Properties for ‘Yoke Cable’

Property

Value

Diameter

100 mm

Normal Drag

1

Normal Inertia

2

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Structure

The Structure component is used to model in-line structures such as PLETs and sled assemblies. In the latter case, the structure is typically combined with a buoy via a cable. The bending stiffness may vary along the length of the structure, and hydrodynamic forces may be optionally modelled. A yoke, if included, is modelled as a rigid element, which is free to rotate within a specified angle. This example contains one Structure component named ‘Structure’, which is added to the Line folder. The various properties associated with the structure are listed in the two tables below.

Table: Geometric Properties for ‘Structure’

Property

Value

Outer Diameter

1000 mm

Thickness

50 mm

Length

20 m

Weight in Air

100 kN

Weight in Water

90 kN

Axial Stiffness

1.0E+13 kN

Torsional Stiffness

1.0E+12 kNm²/rad

 

Table: Bending Stiffness Properties for ‘Structure’

Percentage of Length (%)

Bending Stiffness (kNm²)

100

1.0E+10

In this example, a yoke is included on the structure. The properties of the yoke are listed in the table below.

Table: Yoke Properties

Property

Value

Length

2 m

Weight in Air

1.75 kN

Weight in Water

1.5 kN

Positive Free Rotation Angle

90 degrees

Negative Free Rotation Angle

90 degrees

Pivot Axial Offset

10 m

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Line Component

At this stage, enough components have been defined to allow for the specification of the pipeline stack-up, which is defined in a Line component named ‘Pipeline’.  A summary of the pipeline stack-up is provided in the table below.

Table: Pipeline Stack-Up

Section

Length

24’’ Pipe

400 m

Structure

20 m

24’’ Pipe

1400 m

 

Support Components

This example contains two Support components to model the supports on both the vessel and the stinger. Both Support components are created in the Stinger folder. One component is a Double V Support, named ‘V-Rollerbox’, and the other component is a Zero Gap O Support, named ‘Zero Gap Guide’. The ‘Zero Gap Guide’ component has a support length of 1.5 m. The properties of the ‘V-Rollerbox’ component are listed in the table below.

Table: Properties of ‘V-Rollerbox’

Property

Value

Support Length

1 m

Roller Length, L1

0 m

Roller Length, L2

2 m

Roller Length, L3

0 m

Roller Angle, Theta 1

30 deg

Roller Angle, Theta 2

0 deg

Contact Stiffness

7500 kN/m

 

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Tensioner Component

A single Tensioner component is created in the Stinger folder and is named ‘Tensioner’. ‘Zero-Gap Guide’ is used as the Tensioner Support.

 

Stinger Section Component

The Stinger Section component is used to model individual sections of a stinger. This example contains a single stinger section, named ‘Stinger Section’, which is stored in the Stinger folder. The Rigid option is selected from the Section Type drop-down list. The section is 12.2 m long and has a single support, ‘V- Rollerbox’, located at 6.1 m along the length.

 

Stinger Component

A Stinger component is created to model the S-Lay stinger. The component is created in the Stinger folder and is named ‘Stinger’. Hinged is selected as the stinger definition option.  The stinger comprises of fifteen ‘Stinger Section’ components, each with its own Absolute orientation, as shown in the table below.

Table: Orientation of Stinger Sections

Stinger Section Number

Section Orientation (degrees)

1

5

2

10

3

15

4

20

5

25

6

30

7

35

8

40

9

45

10

50

11

55

12

60

13

65

14

70

15

75

 

 

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Vessel Component

A Vessel component named ‘Lay Vessel’ is created in the Vessel folder. This component is used to model the lay vessel. The Standard Vessel Profile option is selected from the Profile Options drop-down list. The overall dimensions of the vessel are listed in the table below.

Table: Properties of ‘Lay Vessel’

Property

Value

Length

220 m

Depth of Keel below Origin

15 m

Horizontal Offset from Origin

0 m

Create Solid Profile

No

The Stinger Location and Support Locations are also defined in the Vessel component, the properties of which are listed in the two tables below respectively.

Table: ‘Stinger’ Location

Property

Value

X Coordinate

4.4 m

Y Coordinate

-80 m

Z Coordinate

0 m

Stinger Angle

180 degrees

 

Table: Support Locations on ‘Lay Vessel’

Support Name

X Coordinate (m)

Y Coordinate (m)

Z Coordinate (m)

Tensioner

4.8471

63.2

0

V-Shaped Rollerbox

4.8

51

0

V-Shaped Rollerbox

4.8

38.8

0

V-Shaped Rollerbox

4.8

26.6

0

V-Shaped Rollerbox

4.8

14.4

0

V-Shaped Rollerbox

4.8

2.2

0

V-Shaped Rollerbox

4.8

-10

0

V-Shaped Rollerbox

4.8

-22.2

0

V-Shaped Rollerbox

4.8

-34.4

0

V-Shaped Rollerbox

4.8

-46.6

0

V-Shaped Rollerbox

4.8

-58.8

0

V-Shaped Rollerbox

4.8

-71

0

 

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Seabed Component

A single Seabed component is created in the Model folder and is named ‘Seabed’. The default properties of a rigid seabed, with a zero coefficient of friction in the longitudinal and transverse directions and a slope of zero degrees, are left unchanged.

 

Buoy Component

The Buoy component is used to model point buoys. This example contains a single Buoy component named ‘Buoy’, which is created in the Model folder. The buoy has a Weight in Air value of 5 kN and a Weight in Water value of -90 kN.

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